Apparatus and method for enlarging an incision

Abstract

A retraction system and method are provided for retracting tissues surrounding a surgical site. In one aspect, a method including engaging slide connections between a guide dilator and a plurality of tissue engaging members and sequentially enlarging an incision using the guide dilator and the plurality of tissue engaging members. In another aspect, a method of inserting a plurality of tissue engaging members into an incision including fixing tip portions of the plurality of tissue engaging members in an insertion configuration, advancing the tip portions into an incision, and restricting movement of the tip portions away from the insertion configuration. A guide dilator system comprising an elongate body, a plurality of tissue engaging members, and slide connections between the elongate body and the tissue engaging members is also provided.

What is claimed is: 
     
       1. A retractor for enlarging an incision, the retractor comprising:
 a frame; 
 a plurality of tissue engaging members for being inserted into an incision; 
 a plurality of sliders configured to connect the tissue engaging members to the frame, each slider being shiftable between an extended position and a retracted position; 
 a linear drive mechanism associated with one of the sliders, the linear drive mechanism including a rotatable drive member rotatable in a retracting direction to cause the slider associated with the linear drive mechanism to shift toward the retracted position; 
 a tool-receiving member of the linear drive mechanism operably coupled to the drive member; and 
 a clutch of the linear drive mechanism having a drive mode wherein the clutch couples the tool-receiving member to the drive member so that turning the tool-receiving member in the first direction causes turning of the drive member in the retracting direction, the clutch further including a release mode wherein the clutch decouples the tool-receiving member and the drive member and permits the tool-receiving member and the drive member to turn relative to each other. 
 
     
     
       2. The retractor of  claim 1  wherein
 the clutch shifts from the drive mode to the release mode with turning of the tool-receiving member in a second direction opposite the first direction. 
 
     
     
       3. The retractor of  claim 1  wherein the slider includes a rack and the drive member includes a pinion gear engaged with the rack. 
     
     
       4. A retractor for enlarging an incision, the retractor comprising:
 a frame; 
 a plurality of tissue engaging members for being inserted into an incision; 
 a plurality of sliders configured to connect the tissue engaging members to the frame, each slider being shiftable between an extended position and a retracted position; 
 a linear drive mechanism associated with one of the sliders, the linear drive mechanism including a rotatable drive member rotatable in a retracting direction to cause the slider associated with the linear drive mechanism to shift toward the retracted position; 
 a tool-receiving member of the linear drive mechanism operably coupled to the drive member so that turning of the tool-receiving member in a first direction causes turning of the drive member in the retracting direction; and 
 a clutch of the linear drive mechanism having a release mode wherein the clutch decouples the tool-receiving member and the drive member, 
 wherein the clutch includes cam surfaces of the tool-receiving member and the drive member configured to shift the drive member and the tool-receiving member apart with turning of the tool-receiving member in a second direction opposite the first direction. 
 
     
     
       5. The retractor of  claim 4  wherein the clutch includes a spring biasing together the drive member and the tool-receiving member. 
     
     
       6. A retractor for enlarging an incision, the retractor comprising:
 a frame; 
 a plurality of tissue engaging members for being inserted into an incision; 
 a plurality of sliders configured to connect the tissue engaging members to the frame, each slider being shiftable between an extended position and a retracted position; 
 a linear drive mechanism associated with one of the sliders, the linear drive mechanism including a rotatable drive member rotatable in a retracting direction to cause the slider associated with the linear drive mechanism to shift toward the retracted position; 
 a tool-receiving member of the linear drive mechanism operably coupled to the drive member so that turning of the tool-receiving member in a first direction causes turning of the drive member in the retracting direction; and 
 a clutch of the linear drive mechanism having a release mode wherein the clutch decouples the tool-receiving member and the drive member, 
 wherein the tool-receiving member includes a worm screw and the linear drive mechanism includes a worm gear engaged with the worm screw and coupled to the drive member. 
 
     
     
       7. The retractor of  claim 6  wherein the clutch, in the release mode thereof, decouples the worm gear from the drive member. 
     
     
       8. The retractor of  claim 6  wherein the clutch includes:
 at least one coupling member shiftable between a first position wherein the coupling member couples the worm gear and the drive member and a second position wherein the coupling member decouples the worm gear and the drive member; and 
 an actuator shiftable between a drive position wherein the actuator keeps the coupling member in the first position and a release position wherein the actuator permits the coupling member to shift from the first position to the second position. 
 
     
     
       9. A retractor for enlarging an incision, the retractor comprising:
 a frame; 
 a plurality of tissue engaging members for being inserted into an incision; 
 a plurality of sliders configured to connect the tissue engaging members to the frame, each slider being shiftable between an extended position and a retracted position; 
 a rotatable drive member associated with one of the sliders and rotatable in a retracting direction to cause the one slider to shift toward the retracted position and an extending direction to cause the one slider to shift toward the extended position; 
 a worm gear operably coupled to the drive member; 
 a worm screw engaged with the worm gear and rotatable in a first direction to cause rotation of the worm gear and the drive member coupled thereto in the retracting direction, the worm screw being rotatable in an opposite, second direction to cause rotation of the worm gear and the drive member coupled thereto in the extending direction; and 
 a clutch having a release mode wherein the clutch decouples the worm gear from the drive member and permits the drive member to rotate relative to the worm gear as the one slider shifts toward the retracted or extended position. 
 
     
     
       10. The retractor of  claim 9  wherein the clutch has a drive mode wherein the clutch couples the worm gear to the drive member, and
 the worm screw and worm gear are configured to be self-locking to inhibit rotation of the worm gear and drive member coupled thereto not caused by rotation of the worm screw when the clutch is in the drive mode. 
 
     
     
       11. The retractor of  claim 9  wherein the clutch includes:
 at least one coupling member shiftable between a first position wherein the coupling member couples the worm gear and the drive member and a second position wherein the coupling member decouples the worm gear and the drive member; and 
 an actuator shiftable between a drive position wherein the actuator keeps the coupling member in the first position and a release position wherein the actuator permits the coupling member to shift from the first position to the second position. 
 
     
     
       12. The retractor of  claim 9  wherein the drive member and the worm gear include openings and the clutch includes:
 ball bearings sized to extend in the openings of the drive member and the worm gear; and 
 a release shaft having a neck portion and an enlarged head portion, the release shaft being shiftable between a drive position wherein the head portion keeps the ball bearings extending in the openings of the drive member and the worm gear and a release position wherein the neck portion permits the ball bearings to shift out of the openings of one of the drive member and the worm gear to decouple the drive member and the worm gear. 
 
     
     
       13. The retractor of  claim 12  wherein the drive member includes cam surfaces configured to shift the ball bearings out of the openings of the drive member with turning of the drive member relative to the worm gear when the clutch is in the release mode thereof. 
     
     
       14. The retractor of  claim 12  wherein the clutch includes a spring biasing the release shaft toward the drive position. 
     
     
       15. The retractor of  claim 12  wherein the clutch includes a button mounted to the release shaft. 
     
     
       16. The retractor of  claim 9  wherein the worm screw includes a tool-receiving portion configured to receive a rotary drive tool. 
     
     
       17. The retractor of  claim 9  wherein one of the drive member and the worm gear includes an annular wall and the other of the drive member and the worm gear includes a sleeve extending about the annular wall, wherein one of the annular wall and the sleeve is rotatable relative to the other of the annular wall and the sleeve when the clutch is in the release mode. 
     
     
       18. The retractor of  claim 9  wherein the drive member is rotatable around a first axis and the worm screw is rotatable around a second axis perpendicular to the first axis. 
     
     
       19. The retractor of  claim 9  wherein the worm screw includes a helical tooth with at least a portion of the helical tooth having a trapezoidal thread profile.